Apparatus for treating mineral oils



fOt.-4, 1938. Y M. RFENsKE. UAL- '2,132,151

- APPARATUS Fon TREATI'NG ummm. ons

original Filed Haren 15. 1935 e sheets-Sheet 1 kann,

pct. 4; 193s.

M. n, FENsKE E-r Al.

APPARATUS FOR TREATING HINERAL OILS vorigsmammlmi March-.15,1935 -6sheets-sheet 2 Get. 4, 1938.

M. R. FENsKE ET Ax. APPARATUS FOR TREATING MINERAL OIaS 6 Sheets-Sheet 3Original Filed March 13, 1935 Oct. 4, 1938. M. R. FENSKE L-r'm.l y2.1325151 APPARATUS FOR TREATING' MIHERAL OILS y Original Filed March13, 1935 6 Sheets-Shea?. 4

Oct. 4, 1938. M. R. FENSKE ET AL 2,132,151

APPARATUS FOR TREATING MINERAL OILS Original FiledMaroh 13, 1935 6Sheets-Sheet 5 /Jga www abtomq Oct. 4, 1938. M, R. FENSKE ET AL2,132,151

APPARATUS FOR TREATING MINERAL OILS Original Filed March 13, 1935 5Sheets-Sheet 5 @5f/WM atto: we

Patented oct. 4,1938

UNITED STATI-:s6

PATENT OFFICE APPARATUS FOR TREATING MINERAL AOILS Original applicationMarch 13, 1935, Serial No. 10,932. Divided and this application February13, 1936, Serial No. 63,782,

s claims. (ci. 19e- 46) This invention pertains generally to apparatusfor contacting liquid phases and comprises a division of our copendingapplication Serial No. 10,932, led March 13, 1935.

a The invention pertains more particularly to apparatus of the foregoingcharacter wherein high eiiiciencies are obtained by eiectivelycontacting the liquid phases Without serious channeling. This is'accomplished generally speaking by l causing the liquids to iiowthrough the zone of contact over longitudinally arranged attenuatedpacking members.

While in the following description reference will be made to thecontacting of lubricating oil with ll solvent, it is to be understoodthat the apparatus may be employed for contacting other liquids.

The iiow of the liquid phases during contact will be referred to asbeing countercurrent. This term, however, in certain speciiic instancesis sub- 20 J'ected to a broad interpretation as will appear vhereinafterin the description of such instances. 'lhe longitudinally arrangedpacking members may or may not be separately enclosed.

When they are of the same dimensions and are 25 not separately enclosedto form separate paths for the countercurrently flowing liquids, saidpacking members are usually substantially equally dis` tributedlaterally of the counterflow, and substantially the same amount ofliquid is caused to iiow 30 over each. Thus substantially the sameconditions are causedv to exist throughout any lateral cross sectionofthe counterflow when the process is in operation. Should the packingmembers be of different dimensions, the necessary adjust- 35 ments astodistribution of packing members and/ or of liquid flow may be made toaccomplish the same results.

When the longitudinally arranged packing members are separatelyenclosed, f or instance, by 40 tubes having relatively small crosssections of any desired geometrical shape, the countercurrently flowingliquids are brought into eflicient contact in a plurality of separategroups of countercurrently flowing streams or, in other words, in aplurality 45 of separate phase contacting units. In this case eachliquid is preferably metered into each unit in a manner so that at leastsubstantially the same results are produced by each unit. 4

The countercurrently flowing streams may com- 50 prise solve'nt and oilin which case the heavier of the two liquids will `usually be introducedinto the tower at the top thereof and the lighter at the botom.

' The counterflow, however, may be comprised of u two or more immiscibleor only partially miscible strips of jackl chain, etc.

solvents of different densities in which case the oil may be introducedinto the tower at a point or points intermediate the counterowl Thecounterflow may also comprise oil owing in one direction and a pluralityof solvents introduced at different points along the tower iiowing inthe other direction.

The counterow may also comprise other combinations as well as otherliquids, examples of which will hereinafter appear.

It has been observed that wetting of the longitudinally arranged packingmembers by one and perhaps in some cases two or more phases plays animportant part in the efficiency of contact and the prevention ofchanneling. These longitudinally arranged attenuated packing members ap--pear to act as guiding elements for at least one phase (and possiblytwo or more) as it flows through the tower keeping said phasedistributed laterally of its ow. The attenuations are preferably ofsufliciently small cross section to avoid presenting a pathvof leastresistance of any practicable consequence upon (which terms include'through) itself.

The wetting feature makes it possible to ldisperse the wetting phase (orphases) by virtue of its spreading out into films on the surface of thepacking member or members. It has been ob-v served that these films insome cases collect in drops at points on the packing and become detachedonly to recontact the packing and spread out into lms again. Thiskneading action when present assists in bringing the phase particles tothe surface for contact purposes.

While the capacity of a tower having longitudinally arranged attenuatedpacking members may be increased somewhat `by increasing the crosssections of the packing members, to avoid serious channeling due to toolarge a cross section, the capacity preferably will be increased anddecreased by increasing and decreasing the number of packing members.The periphery of the tower will then be adjusted to conform thereto.

When tubes are not employed the individual longitudinally arrangedpacking members may be of any suitable character,` for instance, theymay comprise rods of any geometrical cross section, Such members maycarry spaced laterally extending protuberances such as discs, spheres,frustums of cones, frustums of double cones, rain-drop shapes or anyother surface of revolution to increase the surface. The protuberanceson each attenuated packing member may overlap the protuberances onadjacent attenuated packing members so that any drops leaving anyprotuberance will at once contact another protuberance furtherdownstream to reform into a lm. 'Ihis arrangement of the protuberancesalso causes the liquids to ow in a circuitous course through the tower.

When tubes enclose individual longitudinally arranged packing members,these members may be constructed as set forth in the preceding paragraphor they may be made up of a large number of separate elements such asRaschig rings or similar` packing. The separate elements may or may notbe connected together since the packing member may acquire its shape byvirtueof the tube wall.

Special types of packing are as follows:

1. Small wire forms such as single turn spirals, polyturn spirals, Hshapes, S shapes; shapes, open rings, ordinary carding teeth, bentcarding teeth and similar forms, all having dimensions comparable to-carding teeth used in the textile industry. These forms are found to beextraordinarily eiiicient, affording a high degree of surface areatogether with a high degree of free space. 2. Adsorbent material such asfullers earth, silica gel, Florida earth, activated charcoal, andv otherltering and contact refining agents which owe their action to what iscalled adsorption. These materials are preferably sufficiently coarse toafford suflicient free space for a practical rate of counterilow.

However. other types of packing may be ernployed, for instance, thetubes may be filled with lack chain.

Thus the attenuated packing members may have any other construction orsurface configuration suitable for phase contact in the manner describedherein including combinations of the foregoing and from the descriptionit can be seen that when a phase ilows over or about an attenuatedpacking member this may be over or about the exterior surfaces or theinterior surfaces of the attenuated packing member or both.

For instance, the rod or the like might be substituted by tubes havingreticular side walls and these reticular tubes might be packed and/ormight carry protuberances on their outer surfaces the same as the rodsor the like.

'Ihe countercurrently flowing liquid phases may be engaged, that iscontacted, continuouslyv throughout the length of the counterflow orthey' may be disengaged, that is caused to assume a layer formation, atone or more points intermediate the ends of the counterow. 'I'hisalternate lengagement and disengagement of phases lcombines in onecontinuous system the advantages of ordinary continuous countercurrentcontact and.

the advantages of batch contact and particularly lbatch countercurrentcontact.

'I'he layer formation also permits the taking off vof side streams.

Any side stream may be further treated, for instance, in continuouscountercurrent for stripping Purposes. v

The contact between solvent and oil may be of the ordinary characterwherein the solvent capacity of the solvent does not vary during thecontact. However, it is particularly beneficial in this process becauseof the avoidance of serious channeling to, set up reux conditions in thetower. This may be accomplished by reducing the solvent capacity of thesolvent in the direction of solvent flow, so that a part of that oilwhich dissolves in the solvent upon entry of the solvent into .carriedback into the precipitation zone.

will ow in the same direction as the original feed oil and will nd itsway back into the solution zone where at least a part will beredissolved and This cycle is continuously repeated. Thus, the borderline materials between oil components of greater and lesser quality orof greater and lesser boiling point according to the solvent employedare repeatedly taken into solution and thrown out of solution andeventually a sharper separation is effected.

A reduction in solvent capacity in the direction of solvent iiow mayalso be employed for fractional precipitation purposes. In this case asolventoil solution is flowed through a tower of the character hereindescribed with the direction of solution flow such that the precipitatewill ow coun-` tercurrently to the solution. The precipitate is thusscrubbed of its more soluble constituents during its fiow'through thetower as a separate phase, these constituents going into solution to.precipitation in stages.

If the solvent-oil'solution ils brought to an unsaturated conditionprior to or uponentry into the tower or towers, for instance, by heatingthe solution or adding more solvent, la solution zonel will be set up ineach tower through which the precipitate must pass. This causes a moreeffective scrubbing of the precipitate.

When a series of towers are employed for fractional precipitationinstages, a part of the precipitate separated from any one tower Amay beflowed countercurrently through another tower further upstream ofsolution flow along with the precipitate formed in said tower. 'Ihemore'soluble components of the former precipitate will go into solutionto replace therein components of lesserisolubility which are added tothe latter precipitate. A lpart of the precipitate separated fromeachtower of a series, except, of course, the very first, may be fed backinto the next preceding tower. Thus, all of the materials are moreeifectively scrubbed.

Reducing the solvent capacity of the solvent in the direction of solventflow may be effected either by reducing the temperature of the solvent,by reducing the concentration of solvent such as by distillation orevaporation, or by adding another solvent which is capable of formingwith the first solvent a solvent mixture -of lower solventcapacity forthe oil.

Further features of the invention reside in the construction,arrangement. and combination of parts, and in the steps, combinations ofsteps, and sequences ofsteps, all of which, together with otherfeatures, will become more apparent to persons skilled in the art yasthe specification proceeds and upon reference to the drawings in which:

Figure l isa sectional elevation of la tower' ii-` Figure 5 is asectional elevation (shown broken) u illustrating a modication of theform of the invention illustrated in Figures 3 and 4;

Figure 6 is a sectional elevation (shown broken) illustrating a furtherform of the invention;

Figure 7 is an elevation partly in section illustrating a still furtherform of the invention;

Figure 8 is a sectional elevation (shown broken) illustrating anotherform of the invention; and

Figure 9 is an elevational view diagrammatically illustrating a mannerof coupling a plurality of towers into a single system.

Referring now to Figures 1 and 2 at I0 is shown. a tower Vcomprising aplurality of tubes II joined at their ends by tube sheets I2 and I3 andsurrounded by a plurality of superimposed chambers I4. Tower I alsoincludes segregating chambers I and I6 respectively at opposite ends oftubes II as well as feeding chambers I1 and I8 also respectively at saidopposite ends.

Liquid from chamber I'I is fed into the upper ends of tubes Il by meansof metering tubes 20 and from chamber I8 into the lower ends of tubes IIby means of metering tubes 2I.

Tubes II preferably contain suitable phase contacting means illustratedat 28, for instance, any of the packing'materials referred to above.However, when tubes I I are of small inner diameter, packing materialsmay not be required.

Liquid may be introduced into or withdrawn from tubes II at any pointintermediate their ends, for instance, by a device 22 which isillustrated as comprising a conduit 23 communicating with tubes I Ithrough a plurality of metering orifices 24.

Chamber Il is illustrated as being surrounded by a jacket 26 andchamber. I8 is illustrated as being surrounded by a jacket 21.

Any suitable means (not shown) may, be employed for introducing heatexchange uid into and withdrawing the same from the various heatexchange chambers.

Tubes Il may have a cross section of any desired geometricalconfiguration and within certain limits of any desired area. The crosssection of tubes II is preferably limited to an area sufficiently smallto prevent serious channeling after the contacting means, for instance,packing 28 has been arranged therein.

The preferred limiting cross sectional area for tubes II will be notonly a function of the type of packingemployed, since the small wireforms referred to above will as a rule permit the use of a larger crosssection without an inordinate falling off of efliciency than Raschigrings or jack chain, but also of the degree of uniformity ofdistribution of the packing in the tube. Since the tubes I I may havesides which are straight or'indented or of other surface configuration,the departure of a tube from a straight or continuous form will have itsinfluence. For this reason a denite limit in cross sectional area whichif exceeded in. size will -no longer demonstrate the substantialincrease in efficiency, which we have discovered results from aconstriction of cross sectional area, cannot be given but may be readilydetermined, for instance by testing the eiciency of single tubes of`different sizes when packed withrthe packing which is to be employed.

It may be stated as a general rule that one should proceed with cautionafter exceeding a cross sectional area equivalent to that of a circulartube in the neighborhood of three inches in diameter, although with theproper selection of packing and a careful' distribution in each tube,

it is possible that larger cross-sectional areas may be employed, whilein other cases smaller `cross sections may be required.

Therefore, the term relatively small cross sectional area when employedin this specication and in the claims is intended to mean a crosssection which when taken in conjunction with the contacting means (ifany) therein is sumciently small to materially increase the contactof 3Ainch, 1 inch, and ofV 1.75 inches in diameter,

and have obtained both eicient heat transfer and efficient phasecontact, although it appears that circular tubes up to about 4 inchesvindiameter might be employed successfully for heat transfer purposes.

Tower I0 is adapted for many different modes of operation. For certainof these modes, it may be greatly simplified in construction as willhereinafter appear.

Certain modes of operation are as follows:

(1) In this mode of operation solvent and oil are contacted by simplecountercurrent flow. The heavier of the two liquids is introduced intothe upper ends of tubes II through chamber I1 and metering tubes 20, andthe lighter of thetwo liquids is introduced into the lower ends of tubesI I through chamber I3 and metering tubes 2|. Due to a difference indensity the two liquids ow countercurrently to each other. These liquidsare emciently contacted without serious channeling in view (l) of theattenuated packing members and/or (2) of the small cross sectional areaof tubes II.

Two immiscible solutions are formed, the lighter of which collects insegregating chamber I5 and the heavier in segregating chamber I6 fromwhich respective chambers they may be withdrawn as desired.

In this mode of operation the temperature may be constant in which casea single heat exchange chamber may be substituted for the chambers Il.

Also, the various devices 22 may be omitted.

(2) In this mode of operation two immiscible or only partially misciblesolvents are counterflowed through tubes II and the oil-undertreatmentis introduced into tubes II at a suitable point or points intermediatethe ends thereof,.f0r instance, through a device 22'midway'between theends of tubes II. All of the liquids will be prevented from seriouschanneling. (3) In this mode of operation the oil is introducedl intothe tower at one end thereof, one solvent is introduced into the towerat the other end thereof, and one or more solvents are intro- 'l ducedat an intermediate point or points. The densities of the solvents are sochosen that they will ow countercurrently to the oil. 'I'he oil as itows through the tower is rst contacted by a mixture of all solvents, andprogressively by one less solvent as the point of entry of that solventis passed, and eventually is contacted by the single solventwhich entersvthe ,tower at the end opposite that of the entry of said oil. All

liquids are intimately contacted without serious channeling.

l tions are set up in the tower.

as the solvent proceeds through the tower and although the solventremains saturated with oil, the concentration of dissolved oil decreasesdue to the precipitation of oil from the solvent caused by thereductionin solvent capacity.

The precipitated materials, being of a density comparable to that of thefeed oil, flow countercurrently to the solvent and back into the zone inwhich the solvent is unsaturated. l

'I'he precipitate in its iiowcountercurrently to the solvent is broughtinto intimate contact with the solvent. Thus, any components in theprecipitate which are relatively more soluble in the solvent thancomponents which are already in solution in the solvent, will go intosolution and displace from solution such less soluble components.

Since these precipitated materials flow into vthe solution zone, furtherquantities of relatively more soluble components thereof go back intosolution. These components are carried back into the precipitation zoneby the solvent.

As al result of the continuous repetition of this cycle, a much sharperseparation of oil components is obtained and the quantity of componentsof the same composition finding their way into 40' both the raffinateand extract phases, is substantially reduced.

Among the advantages over other processes isA that all liquids are.intimately contacted without serious channeling.

'I'he solvent capacity of the solvent may be reduced in the direction ofsolvent :dow (a) by introducing the oil into the tower at a temperaturelower than that of the solvent, for instance, by employing' heatexchange chambers 26 and 21; (b) -by reducing the temperature alongtubes II lin the direction of solvent flow, for instance,

by means oiA heat exchange chambers i4; (c)

by introducing into the tubes Il at one or more points, for instancethrough the devices 22, a

Second solvent-which is capable of forming a mixture with thefirstsolvent of lower 'solvent capacity for the oil: (d) by, reducing thesolvent 1 concentration in the direction. of solvent ilow,

for instance, by withdrawing liquid from tubes Il through any device 22,removing solvent and returning the residuum to the tubes il throughanother device 22 preferably adjacent the point of withdrawal; and (e)by a combination of any two or more of the foregoing, or otherwise.'

If the temperature were reduced in the directionl of oil iiow.precipitation of solvent fromthe oil phase instead of oil from thesolvent phase would result. v While the feed oil may be introduced intotower i0 sothat it will flow through the precipitation zone, .it'may, inmany instances, be desirable to (introduce the feed oil into thesolution zone only so that only the precipitate will flow: through -vthe precipitation zone. The 'former lub-mode of operation will bereferred to as 4a and the latter as 4b.

In mode 4b the oil might be introduced into the tower through any of thedevices 22 at the desired point or points.

Whether the feed oil ows through the precipitation zone as in mode 4a,or whether it flows density of the precipitate is greater than that ofthe solution of solvent and oil, said solution is caused to flowupwardly through the tower.

If the density of the precipitate is less than that 20 of the solution,the solution is caused to ilow downwardly through thetower. Thus, whenoil is precipitated from solution, for instance by any of the means setforth herein, it flows through the tower countercurrently tothe'solution and g5 is scrubbed of its more soluble constituents beforeA it is segregated from, the solution at the end of the tower. I

The scrubbing action is considerably greater when the solution isintroduced into tower i0 in an unsaturated condition, since in-'thiscase a solution zone, as wellias a precipitation zone, is set up in thetower. A saturated solution may y be brought to van unsaturatedcondition by any suitable means, for instance, `by heating or addingmore solvent. v n By running the solution serially through a pluralityof towers in each of which precipitation takes place, either with orwithout the setting up of solution zones, fractional precipitation instages is effected.

' A part of the precipitate separated in any stage may be fed back intoa preceding tower, for instance the next preceding, in a manner so thatvit will now countercurrently to the solution therein. This will increasethe scrubbing efl'ect particulariy if a part of theprecipitate-separated in each stage except, of course, the very rst isfed backinto the next preceding tower. V

(6) In this mode of operation all ofthe liquids pass through the towerin the same direction but one travels at a greater linear rate than theother or others. Because the liquids travel through the tower atdifferent velocities, there is f' a relative flow between the liquidswhich may be referred to as being countercurrent although,

Astrictly speaking, it is not.

To accomplishthe foregoing the liquids which are to form the phases maybe introduced into tower i0 at the bottom thereof and caused to flowupwardly therethrough.

Ii the solvent and oil are mixed to form a solution or are homogeneouslymixed mechanical-v ly, this mixturemay be metered into tubes Il eitherthrough chamber II or through chamber shown, it would be probably morevsatisfactoryu liquids.

Because of the construction of tubes II, the twol phases are contactedwithout serious channeling,

The two phases may be separated by formation into layers which may takeplace in chamber I5, particularly ifthe construction is varied asindicated in dotted lines, by extending the tubes I I into chamber I5 todeliver the phases to chamber I5 at about the level of the interfacebetween the two phases.

The phases may be separately withdrawn from chamber I5 at differentlevels, for instance by means ofthe outlets indicated in full and dottedlines.

When the phases iiow up through the column, chamber I1 need not beemployed. i

On the other hand, the liquids which are to form the phases may bemetered into column I0 through chamber I'I and/or chamber I5 in a mannersimilar to thatA previously described in connection with chambers I 6and I8.

In this case the heavier phase travels down through the column at agreater linear velocity than the lighter phase and is intimately mixedtherewith. Layers of the two phases may be formed in chamber I6 andseparately vwithdrawn through suitable outlets at different levels.'I'he lower ends of tubes I I may be extended as illustrated in dottedlines to a point approximately at the interface between the two layers.

Considering the-foregoing in'conneetion with mode of operation (l)above, it will be seen that to obtain relative movement between the twophases one phase may move through tower IIJ in either direction withoutchange in direction of the other phase, or, in fact, might remainstationary as long as the other phase is in motion.

Therefore, mode of operation (6) may be combined with mode ofoperation 1) or any other mode of operation herein described to causethe one phase to alternate in direction through the tower I0 should thisbe desired, or a contact analogous to that obtained in batch contactingmay be obtained by holding one phase stationary.

-While it may be preferred to have a phase that preferentially wetsthepacking travel faster than vthe other phase, the opposite might beresorted to.

(7) In this mode of operation, the ow of one phase with respect to theother phase, is at an angle less than 180 and greater than 0.

This mode of operation may be combined with any of the previouslydescribed modes of operation.

A tower more suitably adapted to this mode of operation will bedescribed hereinafter.

The desideratum in the operation of tower I0 are (l) that the lighterphase leaving any individual contacting unit shall be of the samecornposition as the lighter phase leaving anyother contacting unit, (2)that the same shall apply withrespect to theheavier phase and (3) that'the two phases shall be homogeneously mixed in the contacting units. Y

In substantially approaching the foregoing it is simpler to make tubesII of the same cross section and length; to provide the same characterof contacting means in each tube; to feed the oil under treatment atsubstantially the same rate into each tube; to feed solvent (orsolvents) at substantially the same rate into each tube; when oil isprecipitated for reflux purposes to cause the same amount ofprecipitation in each tube; and in fractional precipitation to feed thesolution at substantially the same rate into each tube and cause the:same amount of precipitation in each tube.

However, the individual contacting units may diier without departingfrom the spirit of the invention. Such differences may be asto'construction, such as size, length, contacting means or otherwise.

For instance, the individual contacting units may vary as toconstruction but may be matched so that each will deliver lighter phaseof substantially the same composition, and heavier phase ofsubstantially the same composition when oil is fed at substantially thesame rate to each, and solvent (or solvents) is fed at substantially thesame rate to each.

VOn the'other hand, the individual contacting units may be of the sameand/or of different construction but may differ as to capacity. In thiscase, adjustments of the oil feed and/ or of solvent feed may be made tocause therespective phases from any unit to be of substantially the samecomposition as the respective phases from any other unit.

The use of metering tubes' makes it possible to, adjust the feedingrate. of the heavier (or heaviest) liquid (either solvent or oil as thecase may be) to any contactingunit by employing a metering tube for thatunit of the desired capacity. Likewise, the use of metering tubes 2|makes it possible to adjust the rate of feed of the lighter (orlightest) liquid to any contacting unit by employing a metering tubeforthat unit of the desired capacity.

When va liquid (or liquids) is introduced into the column intermediatethe ends thereof as in modes of operation (2) and (3) and possibly (4),

(5), (6) and (7), the use of metering tubes 24 makes it possible toadjust the feeding rate, of this liquid (or liquids) to any contactingunit by employing a metering tube for that unit of the desired capacity.

Thus, the desired balance may be obtained. v

Vmatched as to pressure drop, metering tubes 2l may be omitted, togetherwith their supporting structure. 'Chambers I E and I8 would thus becomea single chamber into which the lighter (or lightest) liquid may be fedpreferably adjacent its top and from which the heavier (or heaviest)solution may be withdrawn adjacent its bottom. The ascending lighter (orlightest) liquid, due to the uniformity of cross sectional area andpressure drop of tubes II will divide equally between the various tubesI I or in other words is metered into the tubes. l j

However, in this variation differences in pressure drop may becompensated for, if necessary or desirable, by adjusting the quantity ofheavier (and/ or heaviest) liquid entering individual tubes 1 II so thatthe respective solutions from any unit 1 will be substantially the sameas the respective solutions from any other unit.

Ii' in this variation the tubes I I are of different cross sectionalarea, the pressure drop through the individual tubes may be adjusted byvarying the quantity of packing and/or the, amountof heavier (and/orheaviest) liquid entering the individual tubes may be adjusted to obtainsolutions from each individual contacting unit of the desiredcomposition. f

In modes of operation (4) and (5) the amount of precipitate produced inany individual contacting unit may also be regulated with or withoutother methods of regulation to obtain the desired balance.

It is thought that the ,two phases may in a sense be considered as adispersed phase and a continuous phase in that one phase may pass infilm and/or drop form through the other, the former being the dispersedphase and the latter the continuous phase. However, since in ahomogeneous mechanical mixture` both liquids are in a dispersedcondition it may be that, at least in some cases. a continuous phase,strictly speaking, does not exist. It is conceivable, however, that -insome cases it would be possible by control of the feed to maintain onephase continuous and the other dispersed. In such cases it would bepreferred to disperse the phase which preferentially wets the packing,although the opposite may also be resorted to.

When the phase-which preferentially wets the packing is dispersed thisphase is conducted through each tube over and while wetting the packingmedium and in being so conducted is maintained either entirely in lmform or with a. portion alternately in fllm and drop form. The latteralso affords eillcient contact because of a sort of kneading actioncaused by the drops recontacting the packing and re-spreading out intofilms only to be followed by the formation of more drops. This brings alarge proportion of the liquid particles to the surfacefor contact withthe other phase.

The special packing elements comprising small wire forms herein setforth are unusually eicient in that they afford a very high degree ofsurface area together' with a very high degree of free space. Thesespecial packing elements are, therefore, superior to other packing oi'this type.

A construction in which the attenuated packing members are not enclosedin tubes is illustrated in Figures 3 and 4 in which tower 30 is shown ascomprising a plurality of rods 3| carrying spaced protuberances 32, ashell 33 having a jacket 34, a feeding chamber 35, a segregating chamber36, and a combined feeding and segregating chamber 31. v

Rods 3| may be supported in tower 30 in any suitable manner, forinstance as illustrated.

' Extending downwardly from feeding chamber 35 about each rod 3| is ametering tube 39, which is arranged so that the metered liquid will bedeposited onto the rod. Tubes 39 are of suiiicient length to form withtheir supporting plate 40 and the upper end of shell 33 a segregatingchamber 33.

The lower end of each rod 3| is illustrated as being surrounded by a`segregating tube 4| which forms with the rod-an annular space for thedownward flow of liquid adhering to the rod. The lower end of each tube4| is provided with a plu- -rality of apertures 42 to permit said liquidto flow into chamber 31. j

Each tube 4| is -illustrated as extending beyond the upper end ofchamber 31 and with its upper end surrounded by a tube 43 in such amanner as to afford an annular space 44 between the tubes for meteringpurposes.

The dises 32 on each rod 3|. are illustrated as 'overlapping the discs32 on adjacent rods 3|.

In describing the operation-of tower 33 it will be assumed that theheavier phase prefereni tially wets the rods 3| and discs 32.

The heavier liquid flows from chamber 33 down through metering tubes 33onto the respective rods 3|, continues on down through the tower whileadhering to rods 3| and discs 32,'collects in tubes 4|, drains outthrough apertures 42 to form a layer in chamber 31, and is withdrawn Ifany drops of this liquid leave any packing member, such drops almostimmediately recontact another packing member and return to film form. v

'I'he lighter liquid enters chamber 31 at 41 and occupies the upper partof chamber 31.- This liquid is metered up through the annular spaces sand thus is distributed laterally of the tower vAs the lighter phaseflows up through the tower it intimately contacts the heavier phase.

The lighter solution collects in segregating chamber 36 and is withdrawnthrough outlet 48.

If the lighter phase wets the packing in prefer- Aence to the heavier,tower 30 might be constructed up-side-down. 'I'he lighter liquid wouldthen be metered onto rods 3| by tubes 33 and the heavier liquid would bemetered laterally of the tower by annular spaces,

Other suitable means may be provided for metering the liquids and/or forseparating the final phases. For instance, tubes 4| and 43 might beeliminated. The separation in chamber 31 would then be by simple layerformation, and the lighter liquid would be distributed laterally of thetower by virtue of its layer. .This arrangement might be preferred, forinstance,

when the continuous phase preferentially wets.

the attenuated packing members.

It is, of course, possible to shape the protuberances 32 so as tosubstantially avoid the formation of drops, for instance, by makingprotuberances 32 frustums of cones with the small base pointingdownstream of the wetting liquid flow or of similar shape, for instance,with the surface between the large and small base concave or convex. Aconcave surface would assist in directing the non-wetting liquid througha circuitous course without a material increase and possibly a decreasein pressure drop through tower 30. Protuberances 32 might also beshaped` as rain-drops and arranged, for instance, with the nose pointingdownstream of the wetting liquid flow and with the tail pointingupstream thereof, or vice versa. e

For the purposes of .clearness a limited lnumber of attenuated packingmembers has been shown in the drawings with the volume of ,free spacefairly large compared to the surface area of the packing. It is to beunderstood, however, that the attenuated packing members may be asdensely grouped as desired and may be provided with any desired numberof protuberances.

If one or more of the liquids should find a. path of least resistancealong the inner wall of shell 33, bales might be attached to this wallto cause such liquid or liquids to ilow back toward the attenuatedpacking members and to become redistributed.

A manner of metering liquid onto rods 3| intermediate the ends or toweran is illustrated in Figure in whichfeeding section I3 may be consideredas being interposed intermediate the ends of shell 33 of Figure A3. Thecorresponding parts of shell 33 are identified as 33a. of Jacket 34 as34a, of rods 3| as 3| a, and of protuberances 32 as 32a.

Feeding section 50 comprises a chamber 5| formed by tube sheets 52 and53 between which extend a plurality of imperforate tubes 54 and aplurality of perforate tubes 55.

Imperforate tubes 54 are free of any obstructions whereas a rod 3|apassesl down through each perforate tube 55.

Perforations 56 in tubes 55 comprise metering orifices through whichliquid from chamber 5| may be metered onto rods. 3|a. This may bepreferred when the liquid fed intothe tower at the intermediate pointpreferentially wets the attenuated packing members.

However, rods 3Ia may pass through tubes 54 if desired, and orices 56may be employed for distributing said liquid from chamber 5| laterallyof the tower, for instance, in case said liquid does not preferentiallywet the attenuated packing members.

The metering of the various liquids into tower 36, whether atV two ormore points or whether onto the attenuated packing members or not,preferably follows as nearly as possible the principles above set forthin the discussion of tower I'U.

While the metering onto the individual packing members ofthe liquidwhich preferentially wets the packing may be preferred, it is not anindispensable feature and other constructions may be employed, forinstance, in case there should be no clearly dened preferential wetting.While heat exchange jacket 34 has not been illustrated as being dividedinto a number of sections, such construction may be adopted.

Tower 30 may be used for any of the modes of operation heretoforedescribed in connection with the description of tower I0'.

In connection with the description of tower l0, it was pointed out thatthe packing 28 in tubes li may be adsorbent material.

The employment of adsorbent material as packing in the solvent treatmentof a lubricating oil particularly when such treatment is for the purposeof extracting unsaturated, asphaltic,

and/or naphthenic constituents, is especially useful since it assiststhe solvent in segregating these constituents from the other oilcomponents. Unsaturated, asphaltic and naphthenic constituents of an oilare preferentially adsorbed generally in the order named. In the solventtreatment of oil for the purpose of removingy thesel constituents, suchconstituents are preferentially dissolved generally in the order named.

When adsorption and solvent extraction take place simultaneously in thesame sphere of action, the separation is more rapid and/or morecomplete.

That portion of the oil which-is adsorbed is apparently removed from theadsorbent material in whole or in .part bythe solvent. The

degree of this removal depends somewhat upon the solvent employed.

' In case the solvent does not maintain the adsorbent material in arevivified condition,- the adsorbent material may be renewed eitherintermittently, for instance, by repacking tubes Il of tower |0 asrequired, or intermittently or continuously by modifying theconstruction of the tower.

A tower adapted for either intermittent 'or continuous renewal ofadsorbent material packing is illustrated in Figure 6 wherein tower 6|Jcomprises a contacting section 6|, a liquid feeding chamber 62, anadsorbent material feeding Adsorbent material 1li is withdrawn fromtubes t 69 through tubular filters 12 which extend from the lower endsof tubes 69 through chamber 65 and connect with individual units 13 ofwithdrawing means 66.

Each unit 13 is illustrated as comprising a casing 14 and a screw 15housed therein.

' Units 13 as'shown extend into a container 16 in which the withdrawnadsorbent material and any seepage of heavier solution collect.

Screws 15 may be operated individually or in unison, for instance, bythe means illustrated at 11 if desired.

In operation, the heavier liquid is fed from chamber 62 through meteringtubes 68 into tubes The lighter liquid is fed into chamber 65 at 18,forms a layer therein above the layerI of heavier solution, passesinwardly through the walls of filters 12, and ascends through tubes 69wherein it contacts the descending heavier liquid.

'I'he lighter solution thus formed ascends up into filters 1|, passesoutwardly through the walls of the filters and collects in chamber 64from which it is withdrawn at 19.

'I'he heavier solution descends into filters 12, passes outwardlythrough the walls of the filters, and forms a layer in the bottom ofchamber 65 from which it is withdrawn at 80.

The adsorbent material may be fed into chamber 63 by any suitable means,for instance, the means illustrated at 8|. 'I'he feeding is preferablyin a manner so that the upper ends of filters 1| are kept covered.

In the form shown, the adsorbent material descends by gravity throughfilters 1I, tubes 69,

- container 16 by any suitable means, for instance,

by a screw or at intervals through a man-hole.

Any other suitable construction may be substituted for that shown inFigure 6, for instance, one which will cause the adsorbent material toascendl through filters 12, tubes 69, and filters 1|,

so that it may be withdrawn from chamber 63.

Theoretically, this may be accomplished by reversing the rotation ofscrews 15 and supplying the lower ends thereof with the adsorbentmaterial.

Tower is capable of use in any of the modes of operation heretoforedescribed in connection with tower Il), changes in construction beingmade when necessary following the principles above set forth.

For instance, tower 60 may be used in mode of i operationv (6). In thiscase the adsorbent material maybe of any desired mesh. 'I'he ordinarypercolation nlters may be employed for this purpose if desired, but notwith the same eiiiciency since in tower |.0 serious channeling throughthe adsorbent material does not take place when elevated pressures areapplied to the liquids.

The adsorbent material may be introduced intothe tower in any other way,for instance, by forming a slurry of adsorbent material and one of theliquids to be fed into the tower, the slurry being withdrawn with one ofthe solutions formed depending upon the relative densities of thematerials in the tower.

The invention, however, is not limited to this means of simultaneouslycontacting solvent and adsorbent material with, oil since this may beaccomplished by other suitable means, forinstance, in batch operationsor batch countercurrent operations, by methods comparable to those ofcontact ltration.

A form oi' the invention in which disengagement of phases and theformation of layers is effected intermediate the ends of the tower, isillustrated in Figure 7. Tower 90 is shown as being of a constructionsomewhat similar to tower l0 except that tubes 9| are in sections withthe opposite ends 92 and 93 of each tube 9| projecting into a phase-disengagement chamber. These chambers intermediate the ends of tower 90are shown at 94.

To avoid a direct linear ow of ascending liquid or descending liquid orboth through chambers 94, ends 92 or ends 93 (orboth) of tubes 9| mayvbe provided with caps 95. Caps 95 are arranged in a manner to -avoidlocking of the liquids against flow. i

The heavier layer in any chamber 94 will collect about the ends 92 oitubes 9| and will overflow said ends. The upper edges 96 of ends 92 arepreferably arranged in a horizontal plane so that the heavier layer willbe metered into tubes 9|, the quantity metered into any tube 9| beingdetermined by the perimeter of the tube. For instance, if the perimetersof ends 96 are the same, the same amount of the heavier layer will bemetered into each tube 9|.

What has just been said applies equally to the feeding of the heavierliquid from chamber 98 into the ends 92' of the uppermost tubes 9|.

The heavier liquid may be fed into chamber 98 .as illustrated at 99.

The lighterliquid in any chamber 94 will accumulate about the downwardlyprojecting ends 93 of tubes 9| and will overflow said ends. The 'loweredges |00 of ends 93 are preferably arranged in a horizontal plane sothat the lighter liquid will be metered into tubes 9|, the quantitymetered into any tube 9| being determined by the perimeter of the tube.If the perimeters of ends |00 are the same, the same amount of thelighter layer will be metered linto each tube 9|.

What has just been said applies equally to the feeding of the lighterliquidl from chamber |0| into the ends 99 of the lowermost tubes 9|.

'I'he lighter liquid may be fed into chamber |0| as illustrated at |02.

The formation of layers in chambers 94 makes lt possible to feed liquidinto or withdraw liquid from either the oil phase or the solvent phaseor both.

Means for feeding liquidinto or withdrawing liquid from the lighterlayer of any chamber 94 is illustrated at |04, and means for feedingliquid into or withdrawing liquid from the heavier layer of any chamber94 is illustrated at |00.

It is, of course, understood that any number of chambers 94 may beAemployed, that is one or more.

In some instances, it may be desired to feed a liquid directly intotubes 9|, for instance, this may be desired when such liquid is'aprecipitating solvent. For this purpose a device 22 as -shown in Figuresl, 2 and 'I may be employed if desired.

At the ends of tower the lighter solution is segregated in chamber 98 bylayer formation and withdrawn at |06 and the heavier solution issegregated in chamber |0| by layer formation and withdrawn at |01.

Heat exchange with tubes 9| may be effectedv by any suitable means, ifdesired, for instance l Under mode (4a) a part ofthe feed oil would comeoff with a side stream of precipitate, whereas in mode (4b) the sidestream would be precipitate without feed oil.

Under mode (5) fractional precipitation in stages may be effected in asingle tower.

Under mode (1) the various fractions would also vary as to quality orboiling to the solvent employed.

Under modes (2) and (3) similar eilects would be produced. 'f

Tower 90 might also be employed for mode (6).

It should be noted that a fraction taken oil in a side stream may be ofthe poorer quality oil or of the better quality oil if the solvent isselective as to lmolecular type. or the fraction may be o! the materialsof lower boiling point or of the materials of higher boiling point ifthe solvent is selective as -to molecular size. In other words, the sidestreams may be of the solvent phase, or of the oil phase, or both.

Any of the side streams withdrawn from tower 90 may be retreated withsolvent, for instance, for stripping purposes. This may take place in aside tower such as illustrated at |08.

Disengagement of phases between the ends o! a tower may be eilected byother means, without departing from the spirit of the invention.

A tower in which the ow oi one phasewith respect to the other phase orphases is at an angle greater than 0 and less than 180 as called for inmode of operation (7) is illustrated in Figure 8.

In this figure, tower |40 has a construction which is very similar tothat of tower 30 o1'` Figures 3 and 4. The chiefdifferences are theeliminationof tubes 4| and43 of Figure 3, the addition of one or moreplatesv |4| which extend g laterally of the tower |40l and divide saidtower into a plurality/of chambers |42, and the provision of manifolds|43 on opposite sides of chambers |42.

Plates |4| are provided with apertures |44 point according -vided withadjustable valve the ilow of continuous phase vertically moving phasetherethrough in preference to the laterally moving phase.

Branches |46 of manifolds |43 may be promembers |41 so that through theindividual branches |46 may be regulated.

The distribution ofbranches |46 on opposite sides of tower |40, whetherthe tower has a circular, square, rectangular or other geometricalcross`section, is such of branches |46 and into a chamber |42 on oneside and flows out of said chamber |42 and into branches |46 on theother side, such liquid is effectively distributed about the attenuatedpacking' members.

In describing the operation of tower |40 it will be assumed that thephase which is of greater Apart of the other density preferentially wetsthe packing members. If the opposite were true, it would be merelynecessary to construct tower |40 up-side-down.

The liquid which preferentially wets the packing is fed onto rods 3Iathrough metering tubes 39a; the same as in Figure 3. l

'I'his liquid iiows along the attenuated packing members as it descendsthrough tower |40, forms A alayer at the bottom |49 thereof and iswithdrawn at |50.

If the liquid which is to form the substantial or second phase is toprogress countercurrently of the rst phase as in modes of operation (1),(4), and(5) this liquid enters the lowermost chamber |42 of tower |40through a manifold |43, ows transversely of the tower and out of saidchamber |42 through the other manifold |43.-

The latter manifold is connected to the next higher manifold |43preferably on the same side of the tower. The second phase ascends withor without the aid of a pump and enters the'next higher chamber |42wherein it again ows transversely of the tower but preferably in adirection opposite from that in the first case, and leaves said nexthigher chamber |42 through the manifold |43 on the opposite sidethereof.

Tower |40 may be provided with any number of chambers |42 and if saidnumber is even andthe chambers |42 are connected serially in the mannerdescribed same number oftimes in both directions. This tends to preventthe iirst phase from concentrating on one side of the tower.

However, the second phase need not necessarily iiow transversely oftower |40 in opposite directions the same number of times and, in fact,may flow in one direction only should this be desired, or the manifoldsmay be so connected that the second phase is fed to each chamber |42 atthe same time and flows transversely of the tower only once, should thisbe desired. In the latter case the second phase would progress neithercountercurrently nor in first phase. In fact, the second phase may beheld stationary during the contact in which .case

the contact may be compared to that which takes place in batchoperations.

Should it be desired progress in the same direction asv the rst phase asin mode of operation (6), it would be merely necessary to reverse thedirection of vow of the that, as the liquid ows out w the second phasewill flow laterally of the tower |40 the Va. combination of such thesame direction as the to have the second phasel or immiscible solvents.The solvent of greater density would be `fed into the uppermost chamber|42 and the heavier nal phase withdrawn from the lowermost chamber |42or otherwise, and the solvent of lesser density would be fed into thelowermost chamber |42 and the lighter final phase withdrawn from theuppermost chamber |42 or otherwise. The manifolds |43 would be speciallyconnected to avoid locking of the two solvents against flow, The oilmight be fed into the tower through chamber 35a. if cause it.to flow.Otherwise, the oil may be introduced at an-intermediate point, forinstance, by employing a construction such as shown in Figure 5.

its density is such as to in the solvent. The two solvents might f lowin layer form countercurrently or in the same direction through onechamber |42 only, if desired.

In mode of operation (3) the first 'phase might also be comprisedchiefly of oil.

. Protuberances 32a on rods 3| a may have any suitable configuration andhave been illustrated as being frustums of double cones. In thistower,as well as in tower 30,the protuberances 32 or 32a may have any othersuitable shape, for instance, that of a rain-drop with the nose pointingupstream and the tail pointing downstream of the continuous phase flow.They may, how ever. be reversed.

Should the lateral flow of the second phase and/or the precipitation ofmaterials from the second phase cause any substantial quantity of thefirst phase to become 'permanently separated from the attenuatedpackingmembers in any chamber |42, this first phase may be metered back ontorods 3io. by providing apertures |44 with risers |52 and by arrangingtheupper edges |53 of the risers |52y of any plate |4| in. a horizontalplane. Otherwise, the risers |52 may be omitted if desired.

Should the second phase preferentially wet the packing, it may be madeto ow either. vertically or transversely of the tower, the first phaseflowing in the other of the two directions.

The operation of tower |40 would be somewhat similareven though therewere no well dened preferential wetting, care being taken to permit thedesired separation of phases in chambers |42.

` A plurality of any of the foregoing towers or towers may be connectedtogether in a manner so as to adapt such arrangement for a large numberof the foregoing modes of operation.

This is illustrated in Figure 9 wherein towers |6l, |62, |63, and |64are illustrated as being constructed similarly to tower I0.

Upper outlet |65 of tower |6| is connected to lower inlet |66 of towerseparated lportion of the |62 through line |51 in which is shown a heatexchanger |68 and a pump |69.

y Upper outlet to lower inlet |13 in which is shown a pump |16.

|1|` of tower |62 is connected n2 of tower' sa through une heatexchanger |14 and Upper outlet |11v of tower |63 is connected 4^ tolower inlet |16 of tower |64 through line |10 in which is shown aheatexchanger |80 and pump lill. v Upper outlet |83 may lead to areceiver or other point.

Lower outlet '|85 or tower |64 is connected to upper inlet |06 of tower|63 through line |91 in which is shown a pump |99 and heat exchanger|99.

Lower outlet |9| of tower |99 is connected to upper inlet |92 of tower|92 through line |99 in which is shown a pump |94 and heat exchanger|99.

Lower outlet |91 of tower |92 is connected to upper inlet |99 of tower|9| through line |99 in which is shown a pump 299 and heat exchanger29|.

Lower outlet 299 oi' tower |9| may lead to a receiver or other source.

Tower |94 294 and tower 299.

In mode of operation (1) the lighter phase enters the system at 299,iiows up through tower |9|, down through line |91, up through tower |92,down through line |19, up through tower |99, down through line |19, upthrough tower |94, and out oi' the system at |99.

'I'he heavier phase enters the system at 294, ilows down through tower|94, up through line |91, down through tower. |99, up through line |99,down through tower |92, up through line 99, down through tower |9l, andout of the system at 299.

Ii' desired side streams of the lighter phase might be taken oi! at 2|9,2|| and/or 2|2 and/or side streams of the heavier phase might be taken|9| is provided with a lower inlet Y oi! at 291, 299 and/0r 299.

In the mode of operation (4a) the ilow is the same except that thesolvent capacity .of the solvent is reduced in the direction of solventow. For instance, if the solvent enters at 299, tower 9| may be operatedat the highest temperature, tower |92 at the next highest temperature,tower |99 at the next highest temperaturemightbereduced inw towers |94,|93,

of precipitated oil perature and tower |94 at the lowest temperature;or, the temperature of the lighter phasemaybegraduallyreducedinsuccessionbyheat exchangers |99, |14, and |99;orboth. The temin any other manner, for instance, along the towersthemselves.

A precipitating solvent might be introduced |92 and/or |9|. at anydesired point with or without the reduction oi temperature previouslyreferred to.

Precipitation of oil might be effected by other means, for instance, byevaporation or other removal of solvent in place of or in addition toreduction in temperature and/or addition o! another solvent.

Ii the solvent were introduced at 294 the temperature would, of course,be progressively neduced in the opposite direction through the systemfrom that just descri Ifdesiredsidestreamsofthelighterphase might betaken oi'i at 2|9, 2|| and/or 2| 2 and/or side streams of the heavierphase might be taken ci! at 291, 299 and/or 299.

In mode of operation (4b) if the solvent were introduced into the systemat 299, and the oil at |99, side streams of precipi be taken oi! at 291,299 and/or 299.

Iftheoilwereintmducedat |92,sidestreams might be taken oi! at 299 and/or299 or, if'the oil were inttoducedat |99, aside stream of precipitatedoil mightbe taken oifat299. y

Ifthesolventwereintrodueedintothesystem at 294, the-'oil ,misht enterthesystem at |19, |12 and/or |99 and side streams of precipitated oilmight be taken oi! at outlets 2|9, 2|| and/or 2|2.=dependlng upon theentry oi' oil.

is provided with an upper :niet

Side streams of either phase, o t course, might be taken off at otherpoints if desired.

It is to be noted, however, thatno side stream need be taken oif.

It will be seen that modes and (4b) might be combined.

In mode of operation (5) the solution may enter at 295 or at 294depending upon the relaoi' operation (4a) tive density of theprecipitate.

Assuming that the solution enters at 299, the rst stage precipitate.will be taken oit at 299.

The solution will enter column |92 at |99 either in the saturatedcondition in which it leaves column |9| or inran unsaturated conditionby virtue of the addition of heat, for instance, at heat exchanger |99or of the addition of solvent, for instance, at |99.

'Ihe second stage precipitate will be taken ci! at 291:

In a similar manner the solution ilows through columns |69 and |94, andthe third and fourth stage precipitates are taken oil. at 299 and 299respectively.

If only a part of the precipitate is withdrawn at each oi' 291, 299,and299 we have the condition of a part of the precipitate in each stageexcept the very first, being fed back into the next preceding tower.Theiirst stage precipitate may, of

course, comprise merely scrubbed precipitate fed back from the secondstage, in which case tower |9| would not be operated to directly causeprecipitation.

In mode of operation (2) one solvent enters at 299, the other at 294.-and the oil may enter at |99, |99, |92, |12, |99, |19 and/or any otherintermediate point or points.

In mode of operation 3) the oil may enter at 299 or at 294 dependingupon its relative density with respect to the solvents, and the solventsmay enter at any dedred number of points` along the iiow of the oil.

'Ihe term solvent as used herein includes a solvent. Also the termsolvent includes any compound ormixtureotcompounds whetherin the liquid,solid or vapor phase at normal temperatures and pressures The termmineral oil as used herein includes a lmixture of mineral oil fractionsor s. mixture containing a mineral oil fraction, for

,instance highly viscous lubricating oil thinned with solvent toincrease fluidity.

The tenus substantially uniform". suhstanf tlaiiy uniformly","substantially equal, substantially equally, "substantially identical,and .substantially identically when used herein in-` clude uniform,uniformly, equal, equally, identical, and identically, respectively.mixture of solvents when used in place of a singleItis,ofcourse,understoodtl'iattheteinpera'- tureatsometimeduringthetreatmentwill be such as to permit the formation of twophases and/or the separation ot said phases except, of

course,v should the modes of operation be ein-` ployed form a singlesoiutionof all of the influence upon height since operation adopted.

It will also be understood thatthe contacting sections of any vof thetowers described herein may have any desired height. In choosing suchheight consideration will, of course, be given to the number oftheoretically perfect batch contacts desired in the particularcontacting section. The efficiency of the packing will have its -for thesame results a more efficient packing will require a lesser height thana less eilcient' packing.

In one setup similar to that of. Figure 1 having a contacting sectionequivalent to about forty feet with jack chain as packing in the tubes,between eight and twelve theoretically perfect batch contacts wereobtained, depending upon the mode of The height per theoreticallyperfect batch contact might have been considerably reduced bysubstituting the small wire forms referred to above in place of jackchain.

It will be seen that a fundamental characteristic of similarly betweenthe several modes of operation and towers described herein is found inthe formation and maintenance of a plurality of separate streams of atleast one phase, this plurality of separate streams of one phase beingbrought into intimate contact with the other phase in a manner affordinga high rate of lateral diiusion between the phases with a low rate oflongitudinal diffusion in the individual phases.

Either phase may comprise any liquid or mixture of liquids whether inthe solid, liquid, or vapor phase at normal temperatures and 4pressures,the treatment of mineral oil and more particularly lubricating oil withysolvents being set forth herein as a specific example.

A further fundamental characteristic of similarity resides inthe solventtreatment of mineral oils and the various steps pertaining thereto.

The various towers,`modes of operation, and steps herein particularlydescribed represent specic examples of applying the invention which isintended to be limited only as required by the prior art. Therefore,changes, omissions, additions, substitutions and/or modications mightbeV made without departing from the spirit of the invention.

For convenience in description, the terms vertically. and uprightly asused in the specification and in the claims in describing thepositioning of the attenuated packing members is intended to include notonly a positioning wherein the packing members are perpendicular to thehorizon but alsoa positioning wherein they are sufficiently so tofunction for the purposes set, forth herein.

Also for convenience in description the term "rod as used inthe'specication and claims in describing the structure of certainattenuated packing members is used broadly and includes any otherstructure capable of a similar function whether it be. solid or hollow,imperforate or perforate, unitary or articulated, or a connected seriesof links or ringsvsuch as jack chainor otherwise.

Reference is made. to certain of applicants col pending applicationsas-follows: Serial No. 688,- 416, filed September 6, 1933; Serial No.699,656 filed November 2l, 1933; Serial No. 697,344 led November 9,1933; Serial No. 697,858 filed November 13, 1933; Serial ber 14, 1933;and Serial 1934.

We claim: l

1. Apparatus for contacting liquid phases such as in the solventtreatment of mineral oils com- N0. 735,026 -led July 13,

No. 697,990 filed Novemprising a column, a phase contacting zone in saidcolumn, and a plurality of attenuated packing members verticallyarranged in said phase contacting zone and extending continuouslytherethrough, each lattenuated packing member comprising a rod having aplurality of protuberances arranged in spaced .relationship thereon withthe protuberanc'es on each packing member staggered with respect to andoverlapping the protuberances on adjacent packing members.

2. Apparatus comprising, a column, a plurality of attenuated packingmembers vertically arranged in said column, said packing members beingseparated from each other, means for causing a mineral oil and asolventto now countercurrently through said column, and means for feedingatleast one of said liquids onto said attenuated packing members, each.attenuated i packing member comprising a rod having a plurality oflaterally extending protuberances arranged in spaced relationshipthereon.

3. Apparatus comprising, a colum a plurality of attenuated packingmembers vertically ar- .ranged in said column,

being separated from each other, means for causing a mineral oil and asolvent to flow countercurrently through said column, and means forfeeding at least one of said liquids onto said attenuated packingmembers, each attenuated packing member comprising a trod having aplurality of spaced protuberances arranged in spaced relationshipthereon, the spaced protuberances on each attenuated packing memberbeing arranged in staggered relationshipwith and overlapping theprotuberances on adjacent attenuated packing members.

4. Apparatus comprising, a column, means for introducing liquids intosaid column at atleast three vertically spaced points to cause atleasttwo of said liquids to iiow countercurrently to each other through saidcolumn by virtue of a difference in density such as in the solventtreatment of mineral oils, means at each of said points for dividing thefed liquid into a plurality of A two of said liquids to owcountercurrently to each other through said column by virtue of adierence in density such as in the solvent treatment of mineral oils,means at each of said points for dividing the fed liquid into a`plurality of separate streams, means for contacting each separate streamof each liquid in a segregated phase contacting course with a separatestream of each of the other liquids, means for substantially uniformlydistributing each-stream of each separate group of streams laterally oftheir common segreof streams laterally of their said packing membersgated phase contacting course, and means for maintaining the proportionsof the phases in each segregated phase contacting course substantiallythe same.

6. Apparatus comprising, a column, means forV introducing liquids intosaid column at at least three vertically spaced ypoints to cause atleast two of said liquids to ilow countercurrently to veach otherthrough said column by virtue of a difference in density such as in thesolvent treatment of mineral oils, means at each of said points `monsegregated phase contacting course, and

means for establishing substantially uniform contacting conditions ineach segregated phase contacting course.

-'7. Apparatus comprising, a column, a plurality of attenuated packingmembers vertically arranged in said column', said packing m'lembersbeing spaced from each other and comprising rods having a plurality oflaterally extending members arranged in spaced relationship thereon,means for introducing liquids into said column at atleast threevertically spaced points, and means for removing solutions of saidliquids from said column.

8. Apparatus comprising, a column, a plurality of attenuated packingmembers vertically arranged in said column, said packing members beingspaced from each other, each attenuated packing member comprising a rodhaving a plurality of spaced disc-like members arranged in lspacedrelationship thereon, the spaced disc-like members oi' each attenuatedmember being arranged in staggeredrelationship with and yoverlapping thedisc-like members of adjacent attenuated members, means for introducingliquids into said column at at least three vertically spaced points, andmeans for removing solutions of said liquids from said column.

9. Apparatus for contacting liquid phases such as in the solventtreatment of mineral'oils comprising -a column, a phase contacting zonein said column, and a plurality of attenuated packing members verticallyarranged in said phase contacting zone and extending continuouslytherethrough, each attenuated packing member comprising a large numberof superimposed relatively small packing elements held in an attenuatedshape to form a composite attenuated packing member by virtue oi beingenclosed within a tube, and means Afor controlling temperatureconditions about the tubes to maintain the tubes under substantiallyidentical temperature conditions, and means for varying the temperatureconditions at a plurality of points along said tubes.

MERRELL R. FENSKE. WILBERT B. McCLUER.

